Ice cream blender apparatus produce mixed ice cream for consumption using single or multiple combinations of ice cream and additional added ingredients. The blended ice cream generally consists of a single flavor of ice cream and several additives such as nuts, fruit, or candy. The ingredients are introduced in combination into a hopper and stirred by the operator through a mixing paddle mechanism to more generally mix the ingredients into a uniform consistency and distribution. The mixing paddle mechanism is generally attached to a motorized drive source, and the hopper or the mixing paddle are moved into contact with the ingredients in the hopper and blended. Dispensing of the blended mixture is achieved usually by pouring of the blended mixture out of the hopper by the operator or by extrusion from the hopper by the mixing paddle mechanism or other extrusion means.
In a conventional ice cream blender apparatus, a hopper is mounted for reciprocal, straight-line motion at rates sufficient to blend the hopper contents at a single serving per minute. The hopper is typically of conical profile with an opening of six-inch diameter at the open end of the profile, and an extrusion opening at the opposing end of one half-inch diameter. The conical axis of the hopper is oriented vertically, or Y-axis, with its conical axis coincident to the rotating mixing paddle axis, which is also oriented vertically. The mixing paddle and hopper share a similar profile to facilitate the paddle surfaces being able to sweep the interior volume of the hopper and thusly mix the contents.
The hopper can be supported for straight line, or Y-axis, motion by a mounting structure that incorporates linear bearing technology. The hopper can be positioned below the mixing paddle, with the straight line Y-axis motion bringing the mixing paddle into the interior volume of the hopper by motion of the hopper. Conversely, the straight-line motion can also be applied to the mixing paddle, and the mixing paddle brought into the stationary hopper. Alternately, the mixing paddle and hopper can be brought into the common mixing position by straight line Y-axis motion of both the mixing paddle and the hopper. However, because the hopper is typically motivated by the linkages, cams, and connections, elements of both X-axis and Z-axis motion and corresponding axis reaction forces may be present in the reciprocal motion of the hopper. The stroke length, that is the distance traveled by the movable hopper, is generally between about 8 to 14 inches. As a general rule, for a given ice cream blender apparatus, the shorter the hopper stroke, the less affect the X-axis and Z-axis axis reaction forces disturb the alignment of the hopper and mixing paddle, and the less severe the wear on the components providing the desired Y-axis motion. Misalignment as small as between about 0.0005 and 0.0010 inches can result in the loading of bearing and other support components to cause premature failure and misalignment with repeated cycling. As can be appreciated, it is an ongoing objective of the ice cream blending industry to enhance the operation of the hopper by minimizing to the extent possible, any transient X or Z-axis motion in the hopper.
In conjunction with the reciprocal motion of the hopper, a mixing paddle is supported such that rotation of the mixing paddle is about the Y-axis. The rotation is achieved by supporting a shaft on a bearing pair mounted in the fire, to which the mixing paddle has a shaft attachment point. The shaft can be connected to a motorized prime mover through belts/pulleys, chain/sprocket, and/or gears, or combination thereof, such that powering of the motor, or manual operation of the prime mover by the operator, turns the mixing paddle. The mixing paddle is generally turned and continues turning as the hopper containing the ingredients to be blended is brought up into contact with the mixing paddle. The mixing paddle assists in blending the ingredients and the hopper is withdrawn when desired blending consistency is achieved. Contents of the hopper are then extracted or have been concurrently extracted during the blending process using the aforementioned extrusion features of the hopper and mixing paddle if present. The hopper is the component utilizing the Y-axis motion capability, but as mentioned, a mixing paddle or the combination of mixing paddle and hopper may be involved in this motion. Typically, mechanical linkage connection is provided between the operator handle of the ice cream blender apparatus and the hopper Y-axis motion. An electrical circuit containing an actuation switch closes the prime mover circuit upon operator handle motion to activate the motor driving the mixing paddle.
In order to fully appreciate the various aspects of this invention, it is critical to understand certain fundamental features of a typical ice cream blending apparatus. Referring to FIG. 1, an illustration of the typical ice cream blender apparatus will be discussed. The typical ice cream blender apparatus is generally indicated by the reference character 10. The ice cream blender apparatus 10 includes a frame or housing structure 12 having mounted thereon an electric motor 13 with attached pulley 14 on motor shaft 15 that drives a large pulley wheel 16 through belt connection 17. The pulley wheel is mounted on one vertically aligned auger shaft 8 so as to transmit torque between the motor and the auger shaft. The auger shaft rotates in radial bearings 31 and 32 mounted in opposed plates of the frame. The auger shaft axis 19 is coincident to the vertical Y-axis of the ice cream blender apparatus. A mixing paddle 20 is attached to the lower end of the auger shaft, and connected such that it is stationary relative to the auger shaft. Hence rotation of the motor, produces corresponding rotation of the mixing paddle about the Y-axis through the mechanical connections.
The hopper motion assembly generally designated by reference character 30 of a conventional ice cream blender apparatus includes a hopper guide shaft 40, hopper support 41, lower swing lever 68, upper swing lever 70, and operating handle 75. The hopper guide shaft is guided in linear bearings 81 and 82 coaxially mounted in opposed plates of the frame so as to position conical hopper 50 axis 51 coaxial with the auger shaft axis and the Y-axis. This is achieved by attaching the hopper support to one end of the hopper guide shaft, and the hopper to the hopper support temporarily at 52 to allow for removal of the hopper for cleaning and content dispensing while achieving coaxiality during placement. A first end 67 of the lower swing lever is pinned to the second end of the hopper guide shaft at 43 so as to create a pivot joint. A second end of the lower swing lever is pinned to the first end 66 of the upper swing lever at 71 so as to create a pivot joint. The upper lever swing lever is connected at it's second end to fixed point 78 on the frame members to create a pivot joint. The operator handle is also rigidly attached to the second end of the upper swing lever. Hence movement of the operator handle about pivot point 78 moves the upper swing lever about point 78, which moves the lower swing lever, which axially moves the hopper guide shaft, which in turn has the hopper support and hopper attached, and thereby moves the hopper along the Y-axis. By this combination of mechanical connections, the hopper can be moved upwards toward the mixing paddle to place the mixing paddle within the hopper interior volume for ice cream and ingredients to be blended.
The use of pinned joints and linkages/components producing forces non-coaxial with the center-line of the hopper guide shaft causes moment loading to be seen on the hopper guide shaft linear bearings. The hopper guide shaft, having a centerline offset to the auger shaft, also causes moment loading on the hopper guide shaft linear bearings and other components. These loads are generated from the weight of the components attached and the forces associated with contact of the mixing paddle with the hopper and ingredients during blending. All these non-coaxial forces cause premature wear to the bearings, pinned joints, and components, resulting in short life and increased misalignment to the system through contact wear.